Metronidazole may inhibit intestinal colonization with Clostridium difficile

OBJECTIVE: To evaluate the clinical and microbiological efficacy of minocycline in a subgingival local delivery system as an adjunct to tooth scaling and root planing in dogs with periodontal disease. ANIMALS: Nine 4- to 7-year-old Beagles with periodontitis. PROCEDURE: After scaling of teeth and root planing, 2 treatment and 1 or 2 control sites were selected for each dog: treated sites (n = 18) received minocycline hydrochloride periodontal formulation and control sites (n = 12) received ointment base (no minocycline). Gingival crevicular fluid was collected at a baseline (prior to treatment) and at week 4. Clinical and microbiological effects were evaluated and compared among sites. RESULTS: In minocycline-treated sites, clinical indices were significantly decreased at week 4, compared with those at baseline. Minocycline-treated sites were associated with a significant decrease in gingival crevicular fluid, probing depth, and bleeding on probing values, compared with those for control sites at week 4. Compared with that for control sites, total bacteria count in periodontal pockets of minocycline-treated sites had an obvious tendency to decrease by week 4. Proportions of Porphyromonas and Fusobacterium spp were significantly decreased at week 4, compared with proportions at control sites and with pretreatment (baseline) values. CONCLUSIONS: When used as an adjunct to tooth scaling and root planing, minocycline periodontal formulation stimulated favorable clinical and antimicrobial responses.